CodeHealth: Migrate base::Value::Find* in c/b/e/a

Migrate usages of base::Value::FindBoolKey to
base::Value::Dict::FindBool(). For any methods
that were affected, this change also migrates all
the other occurrences of the API v1 base::Value.

Bug: 1187001
Change-Id: Id4542cd6c1d29f16cb601713b1d6304b4f88d910
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4240737
Reviewed-by: David Bertoni <dbertoni@chromium.org>
Commit-Queue: Anthi Orfanou <anthie@google.com>
Reviewed-by: Martin Kreichgauer <martinkr@google.com>
Cr-Commit-Position: refs/heads/main@{#1104979}